In the case of an ischaemic brain infarction, the damaged regions are divided into the ischaemic core zone and the so-called penumbra which surrounds the core. The size of the ischaemic core plus penumbra determines the extent of the damage after ischaemic insult.
Erythropoietin, also called “EPO” for short, is a glycoprotein which occurs naturally in the body with a molecular weight of 30,000 Dalton (W. Jelkman, “Erythropoietin: Structure, Control of Production, and Function”, Physiological Reviews, 1992, Volume 72, Pages 449 to 489). It is an essential growth factor for the production of erythrocytes and was isolated for the first time in 1977.
Erythropoietin has been in frequent clinical use for many years in the case of patients with renal anaemia on kidney dialysis, in order to obtain larger quantities of autologue blood before planned operations and it also hit the newspaper headlines as a blood-doping agent.
Erythropoietin proved itself thereby to be exceedingly well tolerated. The side effects which are relevant are in particular the often therapeutically desired stimulation of the haematopoiesis with polyglobulia and an arterial hypertension which is seldom to be seen. Both effects are to be expected mainly after chronic erythropoietin administering. If necessary, they are relatively easy to remedy by medicinal treatment or by blood-letting.
Intolerance reactions or anaphylactic reactions constitute rarities in the case of erythropoietin.
To date there is no effective therapy for cerebral ischaemia, such as for example for the treatment of stroke patients without operating on the head region of the patient.
In PNAS 1998, Volume 95, No. 8, pages 4635 to 4640, Sakanaka et al. disclose that central administration of erythropoietin in animal experiments offers a protective effect on cerebral neurons. Because of the knowledge that the blood brain barrier cannot be surmounted by larger proteins, erythropoietin is administered directly to the brain tissue, i.e. by direct infusion, in experiments; however such direct infusion is ruled out in humans because of the high risks which are associated with the application and the maintenance of a temporary ventricle drainage, for example of infections or bleeding.
DelMastro L. et al. disclose in Oncologist 1998, 3/5, pages 314-318 that the preventive administering of erythropoietin can prevent anaemia in cancer patients who have been treated with chemotherapy and hence can preventively reduce the risk of such patients with respect to cerebral ischaemia as a result of anaemia caused by chemotherapy. A therapy for an already present cerebral ischaemia, in particular in the case of patients not treated with chemotherapy, is not disclosed therein.
It is thus the object of the present invention to make available a method for the treatment of cerebral ischaemia, a drug for usage in the treatment of cerebral ischaemia and also a means for producing a drug for the treatment of cerebral ischaemia, which can be applied simply and with as few side effects as possible and which is also risk-free.